This invention relates generally to a control unit for a resin bed type water softener and more particularly to an improved microcomputer-based control unit for a resin bed water softener which initiates regeneration of the water softener resin bed only when necessary.
The most common type of water softener is the ion exchange resin-type softener having a tank which holds a bed of resin through which the hard water is passed to remove undesirable minerals and other impurities. The capacity of the resin bed to absorb minerals and impurities is finite and it is thus necessary to periodically recharge or regenerate the resin bed with a regenerant, typically a brine solution so as to restore the capacity of the resin bed for further water treatment.
With the earliest types of water softeners regeneration was effected manually only after it was discovered that the treatment capacity of the resin bed has been exceeded and the water flowing therethrough was no longer soft. In an effort to eliminate the need for manual regeneration, water softener control systems were developed utilizing a mechanical clock which initiated water softener regeneration on a periodic basis, the frequency of such regeneration being set in accordance with the known capacity of the resin bed and the anticipated daily usage of soft water. While mechanical clock-type water softener control units have alleviated the need for manually regenerating the water softener resin bed, such water softener control units are subject to the disadvantage that by regenerating the water softener resin bed at fixed intervals, regeneration may actually be occurring too often if actual soft water consumption is less than the anticipated soft water consumption or not often enough when the actual soft water consumption exceeds the anticipated soft water consumption. Regenerating the water softener resin bed when sufficient capacity still exists to treat an amount of water equal to, or in excess of the anticipated soft water consumption, is wasteful of salt and the water needed in regeneration. Conversely, failure to regenerate the water softener resin bed after the resin bed capacity has diminished to a point below that required to treat the actual quantity of soft water demanded results in hard water leaving the water softener.
In an effort to better regulate the frequency of water softener resin bed regeneration, demand-type water softener control units have been developed which sense the remaining capacity of the water softener resin bed to soften water. Most present day demand-type water softener control units operate to initiate regeneration of the water softener resin bed at an off-peak time, usually 2:00 a.m., if the remaining capacity of the water softener resin bed, as sensed by the control, is less than that required to refine the amount of water which would likely be used prior to the next regeneration interval. While demand-type water softener control units do achieve better regulation of water softener resin bed regeneration than do mechanical clock-type water softener control units, the frequency at which such demand-type water softener control units initiate regeneration is dependent on the selected reserve value representing the anticipated amount of soft water which will be used prior to the next regeneration interval. Since the actual amount of soft water used will likely not remain constant, but will vary greatly from day to day, the chosen reserve value must be made large to assure that soft water will always be produced by the water softener. Thus, regeneration will likely occur at a greater frequency than is actually necessary.
In contrast to the prior art mechanical clock-type water softeners which initiate regeneration on a periodic basis and prior art demand-type water softener control units which initiate resin bed regeneration in accordance with an artificially determined reserve value, the present invention concerns an improved microcomputer processor-based water softener control unit which initiates water softener regeneration when the remaining resin bed capacity as determined from the actual soft water consumption is less than a reserve value calculated in accordance with the actual soft water consumption to assure that the resin bed is regenerated only when necessary.
It is an object of the present invention to provide an improved water softener control unit which utilizes a microcomputer to control water softener resin bed regeneration.
It is another object of the present invention to provide an improved microcomputer based water softener control unit which controls water softener resin bed regeneration in accordance with the remaining capacity of the water softener resin bed to treat water.
It is yet another object of the present invention to provide an improved microcomputer-based water softener control unit which initiates water softener resin bed regeneration when the remaining resin bed capacity as determined from the actual soft water consumption is less than a reserve value calculated in accordance with the actual soft water consumption so that regeneration occurs only when necessary, thereby achieving a savings of regenerant and water.